Well I'm sure they have eggs, oil, and buttermilk in Yankeedom, but finding cornmeal might be a problem. I know from personal experience you can't find grits there. Go here to order you some meal. Get the white, not the blue (unless you like that). Make sure to use an iron skillet to bake it. My little secret is to add a bit of sugar and have about 1/8 inch of pig fat melted in the skillet before you pour in the batter. Sometimes if I can't eat all the bacon I used to make the pig grease I'll crumble it up and mix it in the batter. Oh yes, that is good! Pouring the batter into that hot skillet on top of the oil makes the bottom nice and crispy so it can hold more butter later on. And if you're feeling real Southern, take that left over corn bread, crumble it in a glass, and pour the rest of your buttermilk in it and eat it with a spoon. Mmmmmm, mmmm.
My mother used to buy corn meal in Pennsylvania all the time. It was from Quaker and was sold in a cardboard cylinder just like Quaker oats, except the top of the cylinder was yellow, not orange/red. It was in the flour and oats aisle.
Lol my mama used to eat that cornbread in her buttermilk but the kids thought it was gross. Her cornbread was totally different from my grandma's which sounded like your recipe. Both were good though.
You can get grits up here but I can't vouch for the quality. But there are lots of folks from the South in Chicago.